When we in the PCS union announced the result of our strike vote on Wednesday, Francis Maude declared, "there is no justification for any civil servant going on strike while discussions are continuing".

Today, Danny Alexander, the chief secretary to the Treasury, has proved our union and our members right, and we welcome the decision of the headteachers' union to ballot for action in the autumn. Alexander has now publicly said what ministers have been saying in private for weeks, in effect: "We're happy to talk, but we will raise the pension age, increase contributions, lower accrual rates and we've already imposed reduced indexation through CPI". What's left to negotiate?

My union and others engaged in the talks in the honest hope of a settlement. We talked with the previous government, when part of the ministerial team was John (now Lord) Hutton, and the agreement reached in 2006 was described by Labour cabinet ministers as "a properly negotiated settlement" that "saved £13 billion for the taxpayer".

The coalition government knows this. Ministers have read Lord Hutton's report which showed (see the graph on p10) the falling cost of public sector pensions.

That is why this government has been working so hard to sell the myth that our retired members live in the lap of luxury. In fact retired benefits officers, tax inspectors, court clerks, coastguards and others get an average pension of just £4,200 a year – about £80 per week.

Many people see increasing life expectancy as a reason for cheer; this coalition sees it as an opportunity to cut pensions. But, of course, longevity is increasing most for the highest paid, not for the low and middle income earners that make up PCS membership.

Alexander says those earning less than £15,000 will be protected from paying more. This is less than the equivalent of £7.60 an hour and covers just 4% of civil servants. Even these "protected" staff would still be forced to retire later and get a smaller pension under the government's proposals.

This is a highly political attack on the public sector. The government has announced more than £25bn in business tax cuts since taking office, yet is attacking our pensions despite the fact they have been expertly and independently scrutinised and found to be sustainable. It has attacked welfare and increased VAT, yet scrapped the bank bonus tax.

Of course it doesn't like to portray these attacks as redistribution from poor to rich, but as a battle between public and private. Low-paid private sector workers are exploited by shareholders and executives, not by fellow low-paid workers in the public sector.

The failure of profiteering businesses to provide decent pensions means taxpayers are paying billions more through means-tested benefits. The top executives of those companies walk away with six or seven figure annual pensions while their hard-working staff get nothing.

So why doesn't the government focus on this injustice? The real reason it wants to undermine public sector pensions is because too many private companies want to run our public services but they do not want to pay their workforces a reasonable pension.

Our members will strike on 30 June and continue to take action until the government talks honestly and openly with us. And next time, it will be alongside as many as 3 million public sector workers.